2D/3D多模态医学图像配准算法研究

2D/3D多模态配准在医学影像导航手术中起着重要作用,主要用于提供术前三维图像和术中二维图像的实时信息,帮助医生精准定位病灶,规划手术路径,从而提高手术的安全性和效率。提出了一种2D/3D多模态医学图像配准算法,首先利用Swin Transformer优秀的特征提取能力,构建了初始姿态估计模型,实现姿态参数的快速预测;接着,为了提升整个配准方法的鲁棒性,引入基于Grangeat关系的粗配准方法;最后设计了基于梯度下降的精配准模块,以提升整个配准过程的精确性,且在该模块将Sobel微分算子与归一化互相关结合,提升了参数优化过程中的灵敏度。实验结果表明,所提配准方法在正位和侧位配准中的误差满足配准要求,配准成功率有显著提升。

基于Lie群表示的保体积2D-3D点集配准算法

2D-3D点集配准的目标是寻找三维原始点集与二维目标投影点集之间的对应关系和最优变换.为了给出配准问题的解析解,避免投影引起的体积退化,提出基于Lie群表示的保体积2D-3D点集配准算法.首先,考虑投影矩阵和旋转矩阵的非交换性,引入Lie群表示,将配准问题形式化为一个Lie群优化问题.利用局部线性化方法,将Lie群优化问题转化为一个可计算的二次规划问题.其次,为了避免体积退化,考虑约束变换后的三维点集的投影与二维目标点集的投影具有相同的体积.为便于计算,引入Jensen-Bregman LogDet散度作为保体积正则项,将计算点集的体积差异转化为计算协方差矩阵之间的差异.然后,通过交替求解对应关系和最优变换,形成完整且可解的迭代策略.最后,在两个经典数据集上进行对比实验和消融实验,验证了该算法的精确性和有效性.

3D/2D血管配准的研究进展及临床应用现状

3D/2D血管配准是将不同模态下的血管影像通过特定的配准算法进行空间、时间上的对齐。这项技术实现了不同模态图像之间的优势互补,是医学影像学领域的重大突破。2D影像资料主要通过有创血管造影获得,3D影像主要来自CT、MRI、超声等。3D/2D血管配准可将两种成像技术所获得的血管解剖结构、血管管腔内信息融合起来,为手术方案的制定、术中定位提供重要依据。在临床手术中,主要将其运用于血管介入治疗以及肿瘤切除领域。本文就3D/2D血管配准的研究进展及临床应用现状进行综述。

Modeling time-dependent mechanical behavior of hard rock considering excavation-induced damage and complex 3D stress states

To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main components:a 3D viscoplastic isotropic constitutive relation that considers excavation damage and complex stress state,a quantitative relationship between critical irreversible deformation and complex stress state,and evolution characteristics of strength parameters.The proposed model is implemented in a self-developed numerical code,i.e.CASRock.The reliability of the model is validated through experiments.It is indicated that the time-dependent fracturing potential index(xTFPI)at a given time during the attenuation creep stage shows a negative correlation with the extent of excavationinduced damage.The time-dependent fracturing process of rock demonstrates a distinct interval effect of the intermediate principal stress,thereby highlighting the 3D stress-dependent characteristic of the model.Finally,the influence of excavation-induced damage and intermediate principal stress on the time-dependent fracturing characteristics of the surrounding rocks around the tunnel is discussed.

基于轮廓点相似性测度的2D-3D医学图像配准算法

针对传统配准算法无法适用于成像模糊、对比度低的X光医学图像的问题,本文提出一种基于轮廓点相似性测度的配准技术.首先引入分块双阈值增强策略来提取DRR图像和X光图像的边缘轮廓信息;其次,采用高斯加权欧氏距离计算图像轮廓的相似度;最后通过平衡优化器算法进行迭代优化,得到最优的位姿参数.实验结果表明:本文算法能够精确提取模糊X光图像的边缘轮廓信息,而且可以准确评估其与CT数据的相似度,平均配准成功率超过94%,算法效率和鲁棒性优于传统算法,可用于医疗诊断、放射疗法、图像引导手术等医学活动.

3D and 2D topographic correction to estimated geothermal gradient from the base of gas hydrate stability zone in the Andaman Forearc Basin

Methane gas hydrate related bottom-simulating reflectors(BSRs)are imaged based on the in-line and cross-line multi-channel seismic(MCS)data from the Andaman Forearc Basin.The depth of the BSR depends on pressure and temperature and pore water salinity.With these assumptions,the BSR depth can be used to estimate the geothermal gradient(GTG)based on the availability of in-situ temperature measurements.This calculation is done assuming a 1D conductive model based on available in-situ temperature measurement at site NGHP-01-17 in the study area.However,in the presence of seafloor topography,the conductive temperature field in the subsurface is affected by lateral refraction of heat,which focuses heat in topographic lows and away from topographic highs.The 1D estimate of GTG in the Andaman Forearc Basin has been validated by drilling results from the NGHP-01 expedition.2D analytic modeling to estimate the effects of topography is performed earlier along selected seismic profiles in the study area.The study extended to estimate the effect of topography in 3D using a numerical model.The corrected GTG data allow us to determine GTG values free of topographic effect.The difference between the estimated GTG and values corrected for the 3D topographic effect varies up to~5℃/km.These conclude that the topographic correction is relatively small compared to other uncertainties in the 1D model and that apparent GTG determined with the 1D model captures the major features,although the correction is needed prior to interpreting subtle features of the derived GTG maps.

Drishti Paint 3.2:a new open-source tool for both 2D and 3D segmentation

X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread application,developing an efficient and user-friendly method for segmenting CT data continues to be a formidable challenge in the field.Most CT data segmentation software operates on 2D interfaces,which limits flexibility for real-time adjustments in 3D segmentation.Here,we introduce Curves Mode in Drishti Paint 3.2,an open-source tool for CT data segmentation.Drishti Paint 3.2 allows users to manually or semi-automatically segment the CT data in both 2D and 3D environments,providing a novel solution for revisualizing CT data in paleontological studies.

3D Road Network Modeling and Road Structure Recognition in Internet of Vehicles

Internet of Vehicles (IoV) is a new system that enables individual vehicles to connect with nearby vehicles,people, transportation infrastructure, and networks, thereby realizing amore intelligent and efficient transportationsystem. The movement of vehicles and the three-dimensional (3D) nature of the road network cause the topologicalstructure of IoV to have the high space and time complexity.Network modeling and structure recognition for 3Droads can benefit the description of topological changes for IoV. This paper proposes a 3Dgeneral roadmodel basedon discrete points of roads obtained from GIS. First, the constraints imposed by 3D roads on moving vehicles areanalyzed. Then the effects of road curvature radius (Ra), longitudinal slope (Slo), and length (Len) on speed andacceleration are studied. Finally, a general 3D road network model based on road section features is established.This paper also presents intersection and road section recognition methods based on the structural features ofthe 3D road network model and the road features. Real GIS data from a specific region of Beijing is adopted tocreate the simulation scenario, and the simulation results validate the general 3D road network model and therecognitionmethod. Therefore, thiswork makes contributions to the field of intelligent transportation by providinga comprehensive approach tomodeling the 3Droad network and its topological changes in achieving efficient trafficflowand improved road safety.

Multi-scale Modeling and Finite Element Analyses of Thermal Conductivity of 3D C/SiC Composites Fabricating by Flexible-Oriented Woven Process

Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale proposed in this work are used to simulate the thermal conductivity behaviors of the 3D C/SiC composites.An entirely new process is introduced to weave the preform with three-dimensional orthogonal architecture.The 3D steady-state analysis step is created for assessing the thermal conductivity behaviors of the composites by applying periodic temperature boundary conditions.Three RVE models of cuboid,hexagonal and fiber random distribution are respectively developed to comparatively study the influence of fiber package pattern on the thermal conductivities at the microscale.Besides,the effect of void morphology on the thermal conductivity of the matrix is analyzed by the void/matrix models.The prediction results at the mesoscale correspond closely to the experimental values.The effect of the porosities and fiber volume fractions on the thermal conductivities is also taken into consideration.The multi-scale models mentioned in this paper can be used to predict the thermal conductivity behaviors of other composites with complex structures.

UAV-based transient electromagnetic 3D forward modeling and inversion and analysis of exploration capability

Unmanned aerial vehicle transient electromagnetic(UAV-TEM)is a novel airborne exploration method that offers advantages such as low cost,simple operation,high exploration efficiency and suitability for near-surface exploration in complex terrain areas.To improve the accuracy of data interpretation in this method,the authors conducted a systematic three-dimensional(3D)forward modeling and inversion of the UAV-TEM.This study utilized the finite element method based on unstructured tetrahedral elements and employed the second-order backward Euler method for time discretization.This allowed for accurate 3D modeling and accounted for the effects of complex terrain.Based on these,the influence characteristics of flight altitudes and the sizes,burial depths,and resistivities of anomalies are compared and analyzed to explore the UAV-TEM systems’exploration capability.Lastly,four typical geoelectrical models of landslides are designed,and the inversion method based on the Gauss-Newton optimization method is used to image the landslide models and analyze the imaging effect of the UAV-TEM method on landslide geohazards.Numerical results showed that UAV-TEM could have better exploration resolution and fine imaging of nearsurface structures,providing important technical support for monitoring,early warning,and preventing landslides and other geological hazards.

基于有限元的双唇橡胶密封的3D-2D耦合仿真分析方法研究

以某混动车型为例,通过有限元软件Abaqus建立车载PTC陶瓷电阻加热器上下法兰面的双唇橡胶模型,通过3D-2D耦合仿真的方法,考虑了在螺栓力、温度、压强多因素综合影响下的密封情况。结果表明,通过3D有限元模型计算,随着温度与压强的升高,上下法兰面会有张开量,其中压强的占比约为温度的3倍;将此张开量代入2D有限元模型,修正橡胶的压缩高度,可得到与实际更接近的密封结果。研究结果表明,通过3D-2D耦合仿真的方法,可以更精确地模拟橡胶在实际工作载荷下的密封情况,使在开发前期识别风险,提供先验性知识。

Clinical Outcomes of Complete Mesocolic Excision for Right-Sided Colon Cancer Using 3D Laparoscopy versus 2D Laparoscopy

Objective:To study the clinical outcomes of complete mesocolic excision(CME)for right-sided colon cancer using 3D(three-dimensional)laparoscopy compared to 2D(two-dimensional)laparoscopy.Methods:From January 2022 to December 2023,58 patients with right-sided colon cancer treated at the Affiliated Hospital of Hebei Engineering University were randomly divided into a 3D laparoscopy group(observation group)and a 2D laparoscopy group(control group),with 29 patients in each group.Intraoperative blood loss,postoperative time to first flatulence,length of hospital stay,and incidence of complications in both groups were recorded.Results:There was a statistically significant difference in intraoperative blood loss between the two groups(P<0.05).There was no statistically significant difference in the time to first flatulence between the groups(P>0.05).However,there was a statistically significant difference in the length of hospital stay(P<0.05)and the incidence of complications(P<0.05)between the two groups.Conclusion:3D laparoscopy for CME can reduce intraoperative blood loss,shorten hospital stay,and decrease postoperative complications,showing significant clinical advantages over traditional 2D laparoscopy.

3D与2D腹腔镜根治术对比于开腹术治疗原发性肝癌的疗效分析

评价原发性肝癌(缩写=HCC)实行3D/2D腹腔镜根治术、开腹术的临床疗效。方法 选择2年间入院的99例HCC患者,摸球均分,一组予用3D-腹腔镜根治术,二组予用2D-腹腔镜根治术;三组予用开腹术,较比疗效。结果 组间治疗后的所有指标相比,均是P<0.05。结论 3D-腹腔镜根治术相比于2D腹腔镜以及开腹术而言,其总体疗效更佳,可以优化手术指标,改善肝功能,而且并发症更少,预后也较佳。

3D腹腔镜与2D腹腔镜下全结肠系膜切除术治疗右半结肠癌的临床效果观察

目的探究3D腹腔镜与2D腹腔镜下全结肠系膜切除术(CME)治疗右半结肠癌的效果,为临床治疗提供参考。方法选取2021年1月至2023年3月宣城市人民医院收治的68例右半结肠癌患者为研究对象,进行回顾性分析,根据手术方法不同分为2D腹腔镜组(30例)和3D腹腔镜组(38例)。比较两组患者围手术期指标、肿瘤标志物水平、炎症反应指标水平、并发症发生情况。结果3D腹腔镜组患者手术时间短于2D腹腔镜组(P<0.05);两组患者术中出血量、淋巴结清扫数目、术后肛门首次排气时间、住院时间比较,差异均无统计学意义(均P>0.05)。术后,两组患者糖类抗原125(CA125)、糖类抗原199(CA199)、癌胚抗原(CEA)水平均低于术前,但组间比较,差异均无统计学意义(均P>0.05);两组患者C反应蛋白(CRP)、白细胞计数(WBC)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平均高于术前,且3D腹腔镜组均低于2D腹腔镜组(均P<0.05);两组患者并发症总发生率比较,差异无统计学意义(P>0.05)。结论3D腹腔镜下CME与2D腹腔镜下CME治疗右半结肠癌效果相当,均无明显并发症,且3D腹腔镜下CME手术时间更短,对患者造成的影响更小。

基于2D/3D成像技术的1JC厚板表面质量在线检测系统研发

针对1JC厚板表面质量在线检测,提出了一种2D/3D复合成像的表面检测系统。应用2D和3D成像系统分别实现厚板上下表面无深度变化及有深度变化缺陷的检测和识别,系统均采用深度学习算法进行分类模型的训练和应用。该技术已在宝钢厚板1JC精整线得到成功验证,现场一年多的应用表明,该技术可以有效实现精整线厚板表面缺陷的在线检测和识别。

3D与2D腔镜甲状腺全切术治疗分化型甲状腺癌的对比研究

目的 探讨3D与2D腔镜甲状腺全切术治疗分化型甲状腺癌(DTC)的效果及对甲状腺激素水平,炎症因子[白细胞介素-6(IL-6)、C-反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)]水平的影响,为临床治疗DTC提供依据。方法 选择2021年6月至2022年3月于南通市第一人民医院接受治疗的76例DTC患者,按照随机数字表法分为对照组(38例,采用2D腔镜甲状腺全切术治疗)、观察组(38例,采用3D腔镜甲状腺全切术治疗)。两组患者均随访6个月。比较两组患者围术期指标,手术前后炎症因子、甲状腺激素水平,以及并发症发生情况。结果 观察组术中出血量更少,手术时间更短;术后7 d两组患者促甲状腺激素(TSH)水平较术前均显著升高,游离四碘甲状腺原氨酸(FT4)、游离三碘甲状腺原氨酸(FT3)、三碘甲状腺原氨酸(T3)、甲状腺素(T4)水平均较术前显著降低;术后1 d两组患者血浆白细胞计数(WBC)及血清炎症因子水平均较术前显著升高,而观察组显著低于对照组(均P<0.05);两组患者住院时间、淋巴结清扫数量,术后7 d TSH、T3、T4、FT4水平及术后6个月各项并发症发生率比较,差异均无统计学意义(均P>0.05)。结论 3D与2D腔镜甲状腺全切术治疗DTC对甲状腺激素的影响和安全性均相当,但3D腔镜甲状腺全切术能够提供更清晰的三维立体视觉,治疗更为精准、微创,故具有手术耗时短、术中出血少、术后炎性损伤轻微的优势。

3D打印柔性SiO_(2)气凝胶复合材料的研究

SiO_(2)气凝胶因特殊网络结构而存在优异的性质,如高比表面积、高孔隙率、低热导率和低密度,是优异的保温绝热材料。但SiO2气凝胶机械性能脆弱,导致传统制造方法难以制备复杂和微小型构件,极大地阻碍了SiO_(2)气凝胶在隔热领域的发展和应用。本文通过3D打印直写技术制备了柔性SiO_(2)气凝胶复合材料,通过研究不同聚乙烯醇(PVA)溶液和十八酸钠(C_(17)H_(35)COONa)的含量,找到最佳浆料配比,打印的柔性SiO_(2)气凝胶复合材料在100℃下的热导率低至0.026 W/(m·K),同时具有较好的压缩性能、弯曲性能和疏水性。这项研究为SiO_(2)气凝胶的规模化应用提供一种可能。

基于3D打印技术的甲烷水蒸气重整研究

天然气(主要成分为甲烷)重整是天然气高效清洁利用的重要途径,重整获得富含氢气的重整气,可供固体氧化物燃料电池进行高效发电。甲烷水蒸气重整需要反应器以及负载其上的重整催化剂,基于3D打印技术的多孔结构具有良好的耐高温、抗氧化和结构稳定性等特点,负载Ni基催化剂用于甲烷催化重整可有效提升反应器稳定性,但相关研究较少。采用浸渍法将Ni-CeO_(2)/γ-Al_(2)O_(3)催化剂负载于3D打印制备的多孔结构和金属泡沫反应器,通过催化剂形貌、分布规律、相结构以及热稳定性的表征,研究了重整反应温度、浆料配比、反应器结构等因素对甲烷水蒸气重整效果的影响。结果显示,催化剂的最佳配比是PVA含量为3.5%(若无特殊说明,均为质量分数),Ni含量为19%,CeO_(2)和γ-Al_(2)O_(3)的含量分别为16%和2.5%。重整测试结果表明,负载催化剂前,重整反应温度低于700℃时,Inconel625和泡沫Ni多孔反应器重整得到的氢气浓度均低于13%(体积分数),而重整反应温度高于800℃时,Inconel625和泡沫Fe多孔反应器重整效果接近,但Inconel625稳定性优于泡沫Fe;负载催化剂后,NCA-I(Inconel625)样品始终表现出低于NCA-N(泡沫Ni)和NCA-F(泡沫Fe)的重整性能,这主要是因为NCA-I含有较多的Cr元素,高温下Cr氧化生成Cr2O3氧化膜,阻碍了反应气和Ni的接触,但测试后NCA-I样品表现出优异的稳定性,无明显脆化和断裂现象,可有效提升重整反应器的稳定性。

3D打印实物模型在颈椎疾患住院医师规范化培训教学中的应用和探讨

目的探讨3 D打印实物模型在提高颈椎疾患住院医师规范化培训(简称住培)教学效果中的作用。方法选取参加骨科住培的颈椎疾患学习的住院医师80名为研究对象,随机分为两组,观察组(40人)以幻灯讲解加3 D打印实物模型教学,对照组(40人)采用幻灯讲解教学。课后即时和课后1月分别对住院医师的知识掌握情况和诊疗技术进行现场测试,利用问卷的形式对住院医师的满意度和参与兴趣(10分法)进行调查。结果课后即时观察组的知识掌握情况和对照组相当(P>0.05),但是观察组的诊疗技术测试成绩显著高于对照组(P<0.05),观察组的满意度和参与兴趣评分均显著高于对照组,两者对比差异有统计学意义(均P<0.05);课后1月时,观察组的知识掌握情况和诊疗技术测试成绩均显著高于对照组(均P<0.05)。结论3 D打印实物模型应用于颈椎疾患住培的带教中,可显著提高教学效果,提升住院医师的满意度和参与兴趣,值得在住培教学中推广。

血清25羟维生素D_(3)水平与T2DM周围血管病变的相关性研究

目的 研究血清25羟维生素D_(3)[25(OH)D_(3)]水平与2型糖尿病(T2DM)周围血管病变的相关性。方法 选取2022年1月至2023年12月我院收治的213例T2DM患者,按照是否发生周围血管病变分为发生组与未发生组。对比两组性别、年龄、病程、BMI、25(OH)D_(3)、空腹血糖(FPG)、C肽、糖化血红蛋白(HbA1c)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)、总胆固醇(TC)、颈动脉超声[颈动脉内膜中层厚度(IMT)、颈动脉收缩期峰值血流速度(PSV)]等资料,采用Pearson相关性检验血清25(OH)D_(3)水平、IMT及PSV与T2DM周围血管病变发生的关系;采用Logistic回归分析影响T2DM周围血管病变发生的因素。结果 213例T2DM患者中并发周围血管病变的有83例(38.97%),未发生的有130例(61.03%)。周围血管病变组的25(OH)D_(3)、C肽、IMT及PSV与非周围血管病变组比较,差异有统计学意义(P<0.05)。Pearson相关性发现,25(OH)D_(3)、C肽、IMT与T2DM周围血管病变呈负相关(r<0,P<0.05),PSV与2DM周围血管病变的发生呈正相关(r>0,P<0.05)。经Logistic回归分析结果显示,25(OH)D_(3)、C肽及PSV是T2DM周围血管病变发生的危险因素(OR>1,P<0.05),而IMT是T2DM周围血管病变发生的保护因素(OR<1,P<0.05)。结论 25(OH)D_(3)与2DM周围血管病变的发生密切相关,其机制可能与C肽、IMT及PSV等影响有关,临床应针对上述因素给予合理的干预以减少周围血管病的发生。